Early photoelectric light detectors were based on cesium. Cesium metal has a work function of 3.43 *10^-¹⁹ J. What is the minimum photon energy needed to eject photoelectrons from a cesium surface? A) 4.33 * 10^-¹⁷ J B) 3.34 *10^-¹⁸ J C) 3.43 *10^-²⁰ J D) 3.43 *10^-¹⁹ J E) 1.99 *10^-²¹ J

Question

Quizplus · Accepted Answer

The minimum photon energy needed to eject photoelectrons is equal to the work function of the material. Therefore, the minimum photon energy needed to eject photoelectrons from a cesium surface is 3.43 x 10^(-19) J, which is option D.

Early Photoelectric Light Detectors Were Based on Cesium